Story of Ruby's demon killing knife

Posted by Arni Bergsson on Oct 02, 2015

The demon-killing knife is an ancient supernatural dagger of the Kurds which has the ability to kill demons. It was originally owned by Ruby before passing into the Winchesters' possession, and the team afterwards used it as their most common means of fighting and killing demons. It was implied by Henry Winchester that there may be, or at least have been, other demon knives of the Kurds like it.

When a demon is stabbed with the demon-killing knife in a vital area of their vessel such as the torso, head or neck, the demon inside the vessel will be destroyed almost instantly. (The Magnificent Seven onwards) However, if the demon the knife is used on only receives a non-fatal wound such as a shallow cut or a stab to a non-vital part of its vessel such as the leg, then the knife's effect will not kill the demon, but it will still cause the demon excruciating pain. (It's the Great Pumpkin, Sam Winchester onwards)

Dean successfully kills a demon with the knife. (No Rest for the Wicked)

Though the demon's vessel almost always dies with the demon possessing it when the demon is killed with the knife, this is apparently due to the fatal injury inflicted by the knife rather than the knife's supernatural power against demons; as when Bobby Singer stabbed himself with the knife while under demonic possession, the demon inside him was instantly destroyed while Bobby ultimately survived the stab. (Sympathy for the Devil)

The demon-killing knife is capable of killing any demon stabbed with it, except for Knights of Hell.A regular Knight of Hell such as Abaddon would only suffer a flash of pain from the demon knife's effect before recovering in seconds, (As Time Goes By) while Cain was completely unaffected by the knife. (First Born) Though the demon knife could kill Alastair and Lilith, they were much more resistant to it than lesser demons, to the point that the knife would have to go in very deep and hit a vital area precisely to actually kill them;anything less such as a stab below the shoulder or in the stomach did nothing but pain and disorient Alastair. (I Know What You Did Last Summer, On the Head of a Pin)

The demon-killing knife proves ineffective on angels such as Castiel. (Lazarus Rising)

As well as killing demons, the demon knife is apparently also capable of killing hellhounds. (Caged Heat, Trial and Error) It has also been implied that the demon knife can kill an Antichrist. (I Believe the Children Are Our Future) However, the demon-killing knife is not capable of killing or even wounding angels, having no effect at all on angels stabbed with it. (Lazarus Rising) Though incapable of killing the Four Horsemen of the Apocalypse, the demon-killing knife can still be used to cut off their human forms' body parts such as fingers, although it is unknown if a conventional, non-supernatural knife would have sufficed for this as well. (Good God, Y'All!, The Devil You Know)

While it is only known to kill demonic beings, the demon-killing knife is implied to still be very powerful and/or valuable; Alastair displayed fascination with the knife and noted from his use of it in torturing Ruby that it was "an exquisite piece," (Heaven and Hell) and War likewise commented that it was a "sweet little knife" when he saw Sam and Dean draw it against him. (Good God, Y'All!) On the other hand though, Henry Winchester implied that the demon knife was the very least powerful means of killing a demon. (As Time Goes By)

39 comments

So who made the demon blade and what material did they use? How did they even know it would work when it was made?

Roxanne Halbleib on Jun 09, 2017

I’ve watched Supernatural from the pilot,I’m addicted…you come to my house Supernatural is all you’ll see on the TV…I watch over and over again ! I got my IPAD about a year and half ago and I was opened to a whole new world of AWESOMENESS ! I missed so much great Hoodies and T’s , but I have only 1 Hoodie, SPN ball hat, Moose and squirrel stuffed animals, Buttons, and pictures from the Pittsburgh Con I went to, autograph pictures, and Four pictures I have with them…Go Gold if you get a chance to go to a con….you’ll have the time of your life !

Laurie Diorio on May 08, 2017

In the show Dean wasn’t wearing Boxers when he pulled his pants down and yelled pudding then the camera turns towards the nurse who is actually the Monster called a (Rayth )that has a retractable spike that comes out of the Rayths bottom wrist kinda like Spider-Man but I’m rambling off topic my point is when the camera points back at dean he starts wiggling but being with no pants and defitly just wasn’t shaking his ass and saying pudding nope he was wiggling his bait and tackle if you know what I mean oh and I think the Raytheon was a girl because she defiantly checked out the goods before she escorted the boys back to the day room

Daniel onorio on Apr 16, 2017

I watch Supernatural religiously everyday, I too suffer from Bipolar Depression, I love my hoodie btw, I would truly love to get the cast to sign it. If any way possible email me. Keep on making new shows, glad to see your mom on there now I would love to see John come back. Truly an AWESOME SHOW. GREAT LOVE TO YOU ALL.